From: Steinar H. Gunderson Date: Wed, 3 Sep 2014 13:48:37 +0000 (-0700) Subject: mac80211: support DTPC IE (from Cisco Client eXtensions) X-Git-Url: https://jxself.org/git/?p=carl9170fw.git;a=commitdiff_plain;h=6fd7d0559618ecaadd368d1ea21607a3210e12de mac80211: support DTPC IE (from Cisco Client eXtensions) Linux already supports 802.11h, where the access point can tell the client to reduce its transmission power. However, 802.11h is only defined for 5 GHz, where the need for this is much smaller than on 2.4 GHz. Cisco has their own solution, called DTPC (Dynamic Transmit Power Control). Cisco APs on a controller sometimes but not always send 802.11h; they always send DTPC, even on 2.4 GHz. This patch adds support for parsing and honoring the DTPC IE in addition to the 802.11h element (they do not always contain the same limits, so both must be honored); the format is not documented, but very simple. Tested (on top of wireless.git and on 3.16.1) against a Cisco Aironet 1142 joined to a Cisco 2504 WLC, by setting various transmit power levels for the given access points and observing the results. The Wireshark 802.11 dissector agrees with the interpretation of the element, except for negative numbers, which seem to never happen anyway. Signed-off-by: Steinar H. Gunderson Signed-off-by: Johannes Berg Signed-off-by: Christian Lamparter --- diff --git a/include/linux/ieee80211.h b/include/linux/ieee80211.h index 6c42b9d..26d3553 100644 --- a/include/linux/ieee80211.h +++ b/include/linux/ieee80211.h @@ -1844,7 +1844,8 @@ enum ieee80211_eid { WLAN_EID_DMG_TSPEC = 146, WLAN_EID_DMG_AT = 147, WLAN_EID_DMG_CAP = 148, - /* 149-150 reserved for Cisco */ + /* 149 reserved for Cisco */ + WLAN_EID_CISCO_VENDOR_SPECIFIC = 150, WLAN_EID_DMG_OPERATION = 151, WLAN_EID_DMG_BSS_PARAM_CHANGE = 152, WLAN_EID_DMG_BEAM_REFINEMENT = 153,